Willsy Posted October 31, 2016 Share Posted October 31, 2016 (edited) Just been looking at the PCB photos. Looks like there's no de-coupling capacitors in there at all! Edited October 31, 2016 by Willsy Quote Link to comment Share on other sites More sharing options...
+jedimatt42 Posted October 31, 2016 Share Posted October 31, 2016 Just been looking at the PCB photos. Looks like there's no de-coupling capacitors in there at all! My tomy tutor motherboard is like that as well... just a few around the VDP DRAM, but none on the logic chips or ROMs. I think, if it didn't need it, it didn't have it. I think I heard the 99/2 was aiming at competing with the incoming Timex. -M@ Quote Link to comment Share on other sites More sharing options...
kl99 Posted October 31, 2016 Author Share Posted October 31, 2016 This is how far we get in MAME right now. There seems to be some problem since the emulated computer locks up by a RTWP pointing to itself. Also, the screen is filled with >FFFF (using a SETO), then the text is printed, but this does not look correct. at this title screen there is a keyboard check as far as i know. maybe that is causing for trouble? ciro gets the screen with internal error because of this. playing in my 99/2 right now, maybe i can find out more what is in the memory. Quote Link to comment Share on other sites More sharing options...
kl99 Posted October 31, 2016 Author Share Posted October 31, 2016 (edited) >0000 - >1FFF System Rom (Eprom 1) >2000 - >3FFF System Rom (Eprom 2) >4000 - >5FFF System Rom (Eprom 3) >6000 - >7FFF contains 'FF' (as expected) >8000 - >86FF contains 'FF' ... >9000 - >90FF contains 'FF' ... >A000 - >A0FF contains 'FF' ... >B000 - >B0FF contains 'FF' ... >C000 - >C0FF contains 'FF' ... >D000 - >D0FF contains 'FF' ... >E000 - >EFFF contains 'FF' (should be RAM) ... Edited October 31, 2016 by kl99 Quote Link to comment Share on other sites More sharing options...
+mizapf Posted October 31, 2016 Share Posted October 31, 2016 I don't know how to chain ROM0 to ROM1 and ROM2 to see a combined view. Maybe Michael Zapf can help us here? You can do it outside: Export the ROMs as binary files, use Windows' copy command to create one file from the parts (copy /b rom1.bin+rom2.bin+rom3.bin allrom.bin), and re-import the whole file again (drag the new file from the Explorer into the TIMT window). Or you can define the start address of the respective rom region in the disassembler options window. Quote Link to comment Share on other sites More sharing options...
kl99 Posted October 31, 2016 Author Share Posted October 31, 2016 @mizapf: the snapshot looks a lot like you are not taking the "blank" end-of-line character into consideration. this is the sign for the video controller to release the bus til the end of that row. Quote Link to comment Share on other sites More sharing options...
kl99 Posted October 31, 2016 Author Share Posted October 31, 2016 >0000 - >1FFF System Rom (Eprom 1) >2000 - >3FFF System Rom (Eprom 2) >4000 - >5FFF System Rom (Eprom 3) >6000 - >7FFF contains 'FF' (as expected) >8000 - >86FF contains 'FF' ... >9000 - >90FF contains 'FF' ... >A000 - >A0FF contains 'FF' ... >B000 - >B0FF contains 'FF' ... >C000 - >C0FF contains 'FF' ... >D000 - >D0FF contains 'FF' ... >E000 - >EFFF contains 'FF' (should be RAM) ... It looks like I did some mistake when using the CALL PEEK command. The 99/2 Manual says to use values up to 65535. But I guess they must be signed negative instead, if greater than 32767. So peeking >E000 would be? Decimal: 57344 CALL PEEK(57344-65536,A) ? Will try again tomorrow (Europe Time). Quote Link to comment Share on other sites More sharing options...
+mizapf Posted October 31, 2016 Share Posted October 31, 2016 @mizapf: the snapshot looks a lot like you are not taking the "blank" end-of-line character into consideration. this is the sign for the video controller to release the bus til the end of that row. Could be. Where do you have this information from? Quote Link to comment Share on other sites More sharing options...
kl99 Posted October 31, 2016 Author Share Posted October 31, 2016 Could be. Where do you have this information from? Refered to within the article here: http://ftp.whtech.com/datasheets%20and%20manuals/99-2%20Computer/Byte%2099-2%20article%20(0683).pdf Also talked about/specified here: http://ftp.whtech.com/datasheets%20and%20manuals/99-2%20Computer/TI992_Product_Specification.pdf http://ftp.whtech.com/datasheets%20and%20manuals/99-2%20Computer/TI992_Software_Specification.pdf Quote Link to comment Share on other sites More sharing options...
+mizapf Posted October 31, 2016 Share Posted October 31, 2016 OK, got it. Yes, this feature is actually not implemented ... but worse, there is a lot missing, this is really antique code (wonder that it is not written in cuneiform, I'd say). The HOLD sync is not there, the VIDENA neither ... still some work to be done, but should be doable. Quote Link to comment Share on other sites More sharing options...
+OLD CS1 Posted November 1, 2016 Share Posted November 1, 2016 this is really antique code (wonder that it is not written in cuneiform, I'd say). 1 Quote Link to comment Share on other sites More sharing options...
kl99 Posted November 1, 2016 Author Share Posted November 1, 2016 http://ftp.whtech.com/datasheets%20and%20manuals/99-2%20Computer/TI992_IO_Controller_Chip.pdf http://ftp.whtech.com/datasheets%20and%20manuals/99-2%20Computer/TI992_Video_Chip.pdf http://ftp.whtech.com/datasheets%20and%20manuals/99-2%20Computer/TI992_Tech_Diagrams.pdf Quote Link to comment Share on other sites More sharing options...
kl99 Posted November 1, 2016 Author Share Posted November 1, 2016 (edited) when I CALL PEEK into >E000 by using CALL PEEK(-8192,P) I get values from the RAM. >E000 - >E23F contains >00 I am using this basic program to visualize the content: 90 R=8192*7 100 CALL CLEAR 110 X=8 120 Y=1 130 FOR I=0 TO 191 140 CALL PEEK(I+R-65536,P) 150 GOSUB 390 160 X=X+1 170 IF X<32 THEN 210 180 GOSUB 300 190 Y=Y+1 200 X=8 210 NEXT I 220 CALL KEY(1,K,S) 230 IF S<>0 THEN 250 240 GOTO 220 250 R=R+I 260 GOTO 100 270 H=(D+48)+(D>9)*-39 280 CALL HCHAR(Y,X,H) 290 RETURN 300 P=I+R-7 310 D4=INT(P/4096) 320 D=D4 330 X=1 340 GOSUB 270 350 D3=INT((P-4096*D4)/256) 360 D=D3 370 X=X+1 380 GOSUB 270 390 D2=INT((P-4096*D4-256*D3)/16) 400 D=D2 410 X=X+1 420 GOSUB 270 430 D1=P-4096*D4-256*D3-16*D2 440 D=D1 450 X=X+1 460 GOSUB 270 470 D4=0 480 D3=0 490 RETURN Here are the screenshots: Edited November 1, 2016 by kl99 Quote Link to comment Share on other sites More sharing options...
kl99 Posted November 1, 2016 Author Share Posted November 1, 2016 (edited) >F000 - >F0FB The Product Specification tells us these 252 bytes are part of the Processor RAM (Cpu "on-chip" Ram). The other 6 bytes of the Processor RAM are from >FFFA to >FFFF. In total we have 258 bytes of this on-chip Processor RAM. >F0FC - >FFF9 contains all "FF" (unused, address range was meant to be used by external circuit) Edited November 1, 2016 by kl99 Quote Link to comment Share on other sites More sharing options...
kl99 Posted November 1, 2016 Author Share Posted November 1, 2016 (edited) here you see the last 6 bytes are in use: >FFFA - >FFFF The Product Specification calls those 6 bytes being part of the Processor RAM (Cpu "on-chip" Ram). The other 252 bytes of the Processor RAM are from >F000 to >F0FB (252 bytes). In total we have 258 bytes of this on-chip Processor RAM. The 4Kybte RAM seems to be mapped from: >E000 to >EFFF The Video Controller is using the RAM for its purposes: The Screen Image Table (768 bytes) is from >EC00 to >EEFF according to the Specs. This seems to be correct by verifying the dump snapshot. >EF00 is the Screen Attribute Control Byte (in case of dump it had value >02 or 0b00000010). The Pattern Descriptor Table is in Rom and seems like it is not mirrored into the RAM. Therefore no Character redefinition seems possible, unless you disable the internal Eprom from the Expansion Bus from your Cartridge. I will try to find out where my Basic Program lies. Edited November 1, 2016 by kl99 Quote Link to comment Share on other sites More sharing options...
+mizapf Posted November 1, 2016 Share Posted November 1, 2016 About the implementation in MAME, as I said, this is from 1999/2000, and the only changes that were applied had the purpose of keeping it compiling. There is quite some work to be done; I consider to rewrite the whole video controller, but this should not be too difficult. Nevertheless, I have to learn a bit more about the video support in MAME. Hexbus is greeting again ... still in the queue for the 99/8 ... But at first I'd like to finish TIMT, or else I'm drowning in half-completed jobs. 2 Quote Link to comment Share on other sites More sharing options...
Meadhbh Hamrick Posted March 30, 2017 Share Posted March 30, 2017 TI 99/2 Ad & Byte Article RescansA while ago I downloaded a Bill Cosby print ad and the Littlejohn / Jander article on the 99/2 from ftp.whtech.com. The quality of the scans wasn't great and since the Internet Archive is hosting high quality Byte & Creative Computing scans, I made new PDFs that are MUCH easier on the eyes. What was called "Byte 99-2 article (0683).pdf" on ftp.whtech.com is 992_byte.pdf below.What was called "99-2 ad in Popular Computing (0583).pdf" on ftp.whtech.com is 992_ad.pdf. 992_ad.pdf 992_byte.pdf 4 Quote Link to comment Share on other sites More sharing options...
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